Draw the electron dot structures of

• (a) ethanoic acid.
• (b) H₂S.
• (c) propanone
• (d) F₂.

Let's delve into the electron dot structures, also known as Lewis structures, for the compounds you've mentioned. These structures help us visualize the arrangement of electrons around atoms in a molecule, which is crucial for understanding chemical bonding and molecular geometry.

Electron Dot Structure of Ethanoic Acid (CH₃COOH)

Ethanoic acid, commonly known as acetic acid, has the formula CH₃COOH. To draw its electron dot structure, we start by identifying the total number of valence electrons:

• Carbon (C) has 4 valence electrons, and there are 2 carbon atoms: 2 x 4 = 8.
• Hydrogen (H) has 1 valence electron, and there are 4 hydrogen atoms: 4 x 1 = 4.
• Oxygen (O) has 6 valence electrons, and there are 2 oxygen atoms: 2 x 6 = 12.

Adding these together gives us a total of 24 valence electrons. The structure can be drawn as follows:

• Place the two carbon atoms in the center, with one carbon connected to three hydrogens (methyl group) and the other carbon connected to one hydroxyl group (–OH) and double-bonded to the oxygen atom.

The final structure looks like this:

    H   O
    |   ||
H - C - C - O - H
    |   
    H

Electron Dot Structure of Hydrogen Sulfide (H₂S)

For hydrogen sulfide, H₂S, we begin with the valence electrons:

• Sulfur (S) has 6 valence electrons.
• Each hydrogen (H) has 1 valence electron, and there are 2 hydrogen atoms: 2 x 1 = 2.

This gives us a total of 8 valence electrons. The structure is straightforward:

• Place sulfur in the center, bonded to two hydrogen atoms.

The Lewis structure appears as follows:

    H
    |
    S
    |
    H

Electron Dot Structure of Propanone (C₃H₆O)

Propanone, also known as acetone, has the formula C₃H₆O. Let's calculate the valence electrons:

• Carbon (C) contributes 4 valence electrons, and there are 3 carbon atoms: 3 x 4 = 12.
• Hydrogen (H) contributes 1 valence electron, and there are 6 hydrogen atoms: 6 x 1 = 6.
• Oxygen (O) contributes 6 valence electrons.

This totals 24 valence electrons. The structure can be visualized as follows:

• Place the central carbon atom double-bonded to the oxygen atom and single-bonded to the two other carbon atoms, which are each bonded to three hydrogen atoms.

The resulting structure is:

    H   H
    |   |
H - C - C = O
    |   
    H

Electron Dot Structure of Fluorine (F₂)

Fluorine gas, F₂, consists of two fluorine atoms. Each fluorine has 7 valence electrons:

• Fluorine (F) has 7 valence electrons, and there are 2 fluorine atoms: 2 x 7 = 14.

The structure is simple since it involves a diatomic molecule:

• Each fluorine atom shares one pair of electrons to form a single bond.

The Lewis structure for fluorine gas is:

F - F

In summary, these electron dot structures provide a visual representation of how atoms bond and share electrons in different molecules. Understanding these structures is fundamental in chemistry, as they lay the groundwork for predicting molecular behavior and reactivity.